What are plants you want Planet zoo to add to the game? I personally want them to add lime trees and pampas grass.
The Madagascar octopus tree would be wonderful for lemur enclosures, especially if they add sifakas later. Gingkos would also be quite cool.
As the game matures I wouldn't mind a series of biome themed nature packs at around $6 per pack, be good to have a solid set of mid level plants and ground cover for each biome, as well as some that are useful for garden and landscape scenery.